1. Field of the Invention
The present invention relates to an image recording apparatus, and particularly relates to a technique for making pressing roller means for developing a latent image on a photosensitive medium small in size.
2. Description of the Prior Art
There has been known an image recording apparatus of the system in which a photosensitive medium carrying a latent image formed thereon by exposure means is passed between a pair of rollers while being pressed therebetween so as to develop the latent image.
In the apparatus of such a system, for example, development of a latent image is achieved by making a coloring agent react upon a photosensitive agent including a dye precursor and forming the latent image for coloring through chemical combination with the photosensitive agent, and there are a case where the photosensitive agent and the coloring agent are applied onto a photosensitive medium together with each other and another case where the photosensitive agent is solely applied onto a photosensitive medium while the coloring agent is applied onto another medium separate from the photosensitive one. In the former case, pressing by pressing roller means is required for making the coloring agent react upon the photosensitive agent, while in the latter case, pressing is required not only for making the above reaction but also for transferring an image from the photosensitive medium to the other medium carrying the coloring agent.
The photosensitive medium or the photosensitive medium and the other medium piled up one on one (hereinafter referred to as "photosensitive medium and so on") are fed in one direction by feeding means so as to pass between rollers after being pressed once. In order to surely perform development by means of the above-mentioned reaction or transfer, the photosensitive medium and so on are pessed under high face pressure.
In order to press the photosensitive medium and so on under high face pressure, however, there has been a problem in that the pressing roller means is required to have high pressing capability, and the apparatus becomes large and expensive. Although it is one solution to reduce the roller means in diameter in order make the face pressure high, it is difficult to sufficiently reduce the pressing force since there is a limit in reduction of the diameter of the roller means because of restriction in wear proof on the roller surfaces, etc.